How the backfield shakes out is the biggest question the Redskins face as they open training camp . Guice, former starter Rob Kelley and 2017 draft pick Samaje Perine are all vying to be the feature back alongside third-down star Chris Thompson at a position the Redskins desperately need improvement from after being fifth-worst in the NFL last season.

“It’s a great three-way competition really with Guice, obviously ‘Fat Rob’ and Samaje,” Gruden said Thursday after the first practice of camp. “It’s very, very important to let these guys play it out. They’ve all shown flashes of being good football players at the running back position.”

No one flashes more potential than Guice, who plummeted in the draft from first-round prospect to Washington in the late second. The LSU product fumbled his first carry of camp but shoulders big expectations and has already made quite the impression on his new teammates.

“He’s a stud. He can do it all,” left tackle Trent Williams said. “He’s one of them guys that every team wants to have. He’s an old-school running back: hard to bring down, runs strong and is extremely fast @ his size.”

Guice should get every opportunity to show he deserves to be the No. 1 running back. He split first-team carries with Perine and Kelley on Thursday, though Gruden expects padded practices to provide a better indication of where the race stands.

Kelley came from off the pace to win the starting job as an undrafted rookie during in 2016 and held it last year until knee and ankle injuries ended his season. But with Guice’s buzz and Perine’s pedigree from his time at Oklahoma, Kelley is again an underdog and is perfectly fine with that.

“I’ve been there before,” Kelley said. “I came in as an undrafted guy. It ain’t nothing new to me. It’s just about overcoming it, man. I’m not the first guy it happened to, I’m not going to be the last guy it happens to, so just keep going.”

Only one thing is settled with the Redskins’ running back situation: Thompson is entrenched as a crucial run and pass option for an offense that is transitioning from Kirk Cousins to new quarterback Alex Smith. Thompson is coming off knee surgery and will be eased back in to the crowded group.

As he deals with the frustration of wanting to be full-go, Thompson looks at the running back corps of Guice, Perine, Kelley, Kapri Bibbs and Byron Marshall and sees an abundance of depth.

“It’s ridiculous right now,” Thompson said. “All the guys bring something to the table. So I’m excited about it. We’ve got a few guys that are those bruiser running backs, and then the other half of the guys are all good route runners and stuff. I’m excited about it. It’s definitely going to bring the best out of us.”

Running backs coach Randy Jordan noticed that right away during offseason workouts after Washington drafted Guice. All of a sudden, Guice’s high-energy approach to every snap has forced that sense of urgency for the players looking to hold him off for carries once the season gets underway.

“The biggest thing is there’s a lot of competition in this room,” Jordan said last month. “So when you have that, everything else takes care of itself.”

Guice said a rookie minicamp that getting accustomed to new terminology would be the biggest adjustment from the SEC to the NFL. Once he gets that down, he’ll level some of the playing field with Perine and Kelley, thought he doesn’t want to speculate about how big his role might be.

“I can’t really predict how me and Chris and Samaje and Kelley and all of us are going to be used,” Guice said. “However Jay or Randy want to use us, that’s how it’s going to go.”

NOTES: LB Zach Brown strained his left quadriceps muscle and was held out of team drills for the remainder of practice. ... TE Jordan Reed revealed he had two separate toe surgeries, one on each foot. Reed had a bone removed from each big toe after lingering soreness that has lasted since before training camp a year ago.